Admins are not able to assign rooms in the room preferences page.

On the room preferences page, Admins currently don't have the option to assign rooms for instructors. Add a column that allows admins to assign any room to any class. (UI should be similar to when they are changing room preferences.)

Example of what that might look like.

Note: Keep in mind that there is an algorithm (in `roomAssignment.py`) that already assigns a room to each course. Make sure your change doesn't break it.

files:
`cas/app/static/js/local/roompreferences.js`
`cas/app/templates/roomPreferences.html`